Epidemiologic studies have consistently reported associations between outdoor fine particulate matter (PM2.5) air pollution and adverse health effects. Although Asia bears the majority of the public health burden from air pollution, few epidemiologic studies have been conducted outside of North America and Europe due in part to challenges in population exposure assessment. We assessed the feasibility of two current exposure assessment techniques, land use regression (LUR) modeling and mobile monitoring, and estimated the mortality attributable to air pollution in Ulaanbaatar, Mongolia. We developed LUR models for predicting wintertime spatial patterns of NO2 and SO2 based on 2-week passive Ogawa measurements at 37 locations and freely available geographic predictors. The models explained 74% and 78% of the variance in NO2 and SO2, respectively. Land cover characteristics derived from satellite images were useful predictors of both pollutants. Mobile PM2.5 monitoring with an integrating nephelometer also showed promise, capturing substantial spatial variation in PM2.5 concentrations. The spatial patterns in SO2 and PM, seasonal and diurnal patterns in PM2.5, and high wintertime PM2.5/PM10 ratios were consistent with a major impact from coal and wood combustion in the city’s low-income traditional housing (ger) areas. The annual average concentration of PM2.5 measured at a centrally located government monitoring site was 75 μg/m3 or more than seven times the World Health Organization’s PM2.5 air quality guideline, driven by a wintertime average concentration of 148 μg/m3. PM2.5 concentrations measured in a traditional housing area were higher, with a wintertime mean PM2.5 concentration of 250 μg/m3. We conservatively estimated that 29% (95% CI, 12–43%) of cardiopulmonary deaths and 40% (95% CI, 17–56%) of lung cancer deaths in the city are attributable to outdoor air pollution. These deaths correspond to nearly 10% of the city’s total mortality, with estimates ranging to more than 13% of mortality under less conservative model assumptions. LUR models and mobile monitoring can be successfully implemented in developing country cities, thus cost-effectively improving exposure assessment for epidemiology and risk assessment. Air pollution represents a major threat to public health in Ulaanbaatar, Mongolia, and reducing home heating emissions in traditional housing areas should be the primary focus of air pollution control efforts.

Background

The environment is suspected to play an important role in the development of childhood asthma. Cohort studies are a powerful observational design for studying exposure–response relationships, but their power depends in part upon the accuracy of the exposure assessment.

Objective

The purpose of this paper is to summarize and discuss issues that make accurate exposure assessment a challenge and to suggest strategies for improving exposure assessment in longitudinal cohort studies of childhood asthma and allergies.

Data synthesis

Exposures of interest need to be prioritized, because a single study cannot measure all potentially relevant exposures. Hypotheses need to be based on proposed mechanisms, critical time windows for effects, prior knowledge of physical, physiologic, and immunologic development, as well as genetic pathways potentially influenced by the exposures. Modifiable exposures are most important from the public health perspective. Given the interest in evaluating gene–environment interactions, large cohort sizes are required, and planning for data pooling across independent studies is critical. Collection of additional samples, possibly through subject participation, will permit secondary analyses. Models combining air quality, environmental, and dose data provide exposure estimates across large cohorts but can still be improved.

Conclusions

Exposure is best characterized through a combination of information sources. Improving exposure assessment is critical for reducing measurement error and increasing power, which increase confidence in characterization of children at risk, leading to improved health outcomes.

This is a case study describing how climate change may affect the health of British Columbians and to suggest a way forward to promote health and policy research, and adaptation to these changes. After reviewing the limited evidence of the impacts of climate change on human health we have developed five principles to guide the development of research and policy to better predict future impacts of climate change on health and to enhance adaptation to these change in BC. We suggest that, with some modification, these principles will be useful to policy makers in other jurisdictions.

Objective

To compare the marginal benefit of in-home asthma self-management support provided by community health workers (CHWs) with standard asthma education from clinic-based nurses.

Design

Randomized controlled trial.

Setting

Community and public health clinics and homes.

Participants

Three hundred nine children aged 3 to 13 years with asthma living in low-income households.

Interventions

All participants received nurse-provided asthma education and referrals to community resources. Some participants also received CHW-provided home environmental assessments, asthma education, social support, and asthma-control resources.

Outcome Measures

Asthma symptom–free days, Pediatric Asthma Caretaker Quality of Life Scale score, and use of urgent health services.

Results

Both groups showed significant increases in caretaker quality of life (nurse-only group: 0.4 points; 95% confidence interval [CI], 0.3–0.6; nurse + CHW group: 0.6 points; 95% CI, 0.4–0.8) and number of symptom-free days (nurse only: 1.3 days; 95% CI, 0.5–2.1; nurse + CHW: 1.9 days; 95% CI, 1.1–2.8), and absolute decreases in the proportion of children who used urgent health services in the prior 3 months (nurse only: 17.6%; 95% CI, 8.1%–27.2%; nurse + CHW: 23.1%; 95% CI, 13.6%–32.6%). Quality of life improved by 0.22 more points in the nurse + CHW group (95% CI, 0.00–0.44; P=.049). The number of symptom-free days increased by 0.94 days per 2 weeks (95% CI, 0.02–1.86; P = .046), or 24.4 days per year, in the nurse + CHW group. While use of urgent health services decreased more in the nurse + CHW group, the difference between groups was not significant.

Conclusion

The addition of CHW home visits to clinic-based asthma education yielded a clinically important increase in symptom-free days and a modest improvement in caretaker quality of life.

Background

Contaminants encountered in many households, such as environmental tobacco smoke, house dust mite, cockroach, cat and dog dander, and mold, are risk factors in asthma. Young children are a particularly vulnerable subpopulation for environmentally mediated asthma, and the economic burden associated with this disease is substantial. Certain mechanical interventions are effective both in reducing allergen loads in the home and in improving asthmatic children’s respiratory health.

Results

Combinations of interventions including the use of dust mite-impermeable bedding covers, improved cleaning practices, high-efficiency particulate air vacuum cleaners, mechanical ventilation, and parental education are associated with both asthma trigger reduction and improved health outcomes for asthmatic children. Compared with valuated health benefits, these combinations of interventions have proven cost effective in studies that have employed them. Education alone has not proven effective in changing parental behaviors such as smoking in the home.

Conclusions

Future research should focus on improving the effectiveness of education on home asthma triggers, and understanding long-term children’s health effects of the interventions that have proven effective in reducing asthma triggers.

Pediatric asthma is a growing public health issue, disproportionately affecting low-income people and people of color. Exposure to indoor asthma triggers plays an important role in the development and exacerbation of asthma. We describe the implementation of the Seattle-King County Healthy Homes Project, a randomized, controlled trial of an outreach/education intervention to improve asthma-related health status by reducing exposure to allergens and irritants in the home. We randomly assigned 274 low-income children with asthma ages 4-12 to either a high- or a low-intensity group. In the high-intensity group, community health workers called Community Home Environmental Specialists (CHES) conducted initial home environmental assessments, provided individualized action plans, and made additional visits over a 12-month period to provide education and social support, encouragement of participant actions, provision of materials to reduce exposures (including bedding encasements), assistance with roach and rodent eradication, and advocacy for improved housing conditions. Members of the low-intensity group received the initial assessment, home action plan, limited education during the assessment visit, and bedding encasements. We describe the recruitment and training of CHES and challenges they faced and explain the assessment and exposure reduction protocols addressing dust mites, mold, tobacco smoke, pets, cockroaches, rodents, dust, moisture, and toxic or hazardous chemicals. We also discuss the gap between the practices recommended in the literature and what is feasible in the home. We accomplished home interventions and participants found the project very useful. The project was limited in resolving structural housing quality issues that contributed to exposure to indoor triggers.

Background

Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys.

Results

We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described.

Conclusion

Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.